| /* |
| * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| |
| /* |
| * This header file includes the VAD internal calls for Downsampling and FindMinimum. |
| * Specific function calls are given below. |
| */ |
| |
| #ifndef WEBRTC_VAD_SP_H_ |
| #define WEBRTC_VAD_SP_H_ |
| |
| #include "vad_core.h" |
| |
| /**************************************************************************** |
| * WebRtcVad_Downsampling(...) |
| * |
| * Downsamples the signal a factor 2, eg. 32->16 or 16->8 |
| * |
| * Input: |
| * - signal_in : Input signal |
| * - in_length : Length of input signal in samples |
| * |
| * Input & Output: |
| * - filter_state : Filter state for first all-pass filters |
| * |
| * Output: |
| * - signal_out : Downsampled signal (of length len/2) |
| */ |
| void WebRtcVad_Downsampling(WebRtc_Word16* signal_in, |
| WebRtc_Word16* signal_out, |
| WebRtc_Word32* filter_state, |
| int in_length); |
| |
| /**************************************************************************** |
| * WebRtcVad_FindMinimum(...) |
| * |
| * Find the five lowest values of x in 100 frames long window. Return a mean |
| * value of these five values. |
| * |
| * Input: |
| * - feature_value : Feature value |
| * - channel : Channel number |
| * |
| * Input & Output: |
| * - inst : State information |
| * |
| * Output: |
| * return value : Weighted minimum value for a moving window. |
| */ |
| WebRtc_Word16 WebRtcVad_FindMinimum(VadInstT* inst, WebRtc_Word16 feature_value, int channel); |
| |
| #endif // WEBRTC_VAD_SP_H_ |
